Those pressing for immediate reductions in carbon dioxide emissions face big problems. Here’s one; the prospect of cooling the planet through geoengineering. The people working on this are serious scientists and analysts, not lackeys of Senator Robert Byrd’s (D-WVA) mountain-top removing, coal industry cronies. Rather, they include Paul Crutzen, winner of the 1995 Nobel Prize in chemistry for his ozone hole work. The prestigious journal Climate Change devoted an entire issue to the subject. And geoengineering has been featured in Science and the New York Times.

One proposal is to pump sunlight reflecting sulfur particles into the atmosphere. We’ve had several experiences with the cooling effect of atmospheric sulfur. In 1815, the eruption of Mount Tambora caused the “year without summer.” In 1991, Mount Pinatubo spewed forth enough sulfur to cool the Earth about one degree for several years. That’s about equal to the planetary warming we’ve experienced over the past 100 years.

Other ideas include placing aluminum-coated Mylar balloons into low earth orbit, seeding oceans with iron to stimulate the growth of carbon-consuming phytoplankton, detuning airplane engines so jets “fly dirtier” and emit more carbon soot (the “sunscreen” proposal), and spraying seawater into clouds to increase the albedo effect. All of these proposals would cool the planet without any reduction in CO2 emissions.

Since the mid-nineteenth century, the atmospheric concentration of carbon dioxide has risen from some 280 parts per million (ppm) to around 370 ppm. Fossil fuel combustion accounts for about three-quarters of the increase. Deforestation and changes in land use patterns (mainly in the tropics) accounts for the rest.

We face immense challenges transforming our energy policies and reducing CO2 emissions. First, unlike carbon particles from jet engines, CO2 persists in the atmosphere for centuries. This means reduction is a multigenerational concern. Second, a molecule of CO2 has the same effect whether it’s emitted in Bozeman or Beijing. Hence, global warming requires the commitment, cooperation, and compliance of the developing world. Even if rich countries cut emissions, it will matter little unless China, India, Brazil, and Indonesia follow.

Proponents don’t believe geoengineering is a silver bullet. Rather, it is a valuable stopgap. It buys time while we develop and deploy alternative fuels and figure out acceptable policies to reduce or stabilize atmospheric CO2.

Geoengineering will receive ever more attention from scientists and policy makers, as the hidden costs of schemes like the Kyoto Protocol become obvious. These costs are probably too high for politicians to bear. Despite ratifying Kyoto, and committing to serious CO2 reductions, only two of fifteen EU states (Britain and Sweden) are on track to meet their emissions targets. Between 2000-2004 the U.S. economy expanded 38 percent faster than the EU-15’s. Yet, during the same period, our CO2 emissions growth was half the EU’s.

Of course we can geoengineer the climate—but this raises important questions. Who sets the thermostat? Do residents of the Maldives turn the dial, since a future rise in sea level could submerge their homes? Or do the Russians? They might prefer some moderate warming to increase agriculture in Siberia and provide ice-free ports.

What if a geoengineering approach is successful, popular, and cheap? What are the implications if environmentalists, who have a history of rejecting “technological fixes” e.g., the Green Revolution and genetically engineered crops, fight this? They will risk condemnation for opposing pragmatic solutions to climate change.

Mark Kleiman, of UCLA and a FREE lecturer explores this tension “…why is this [geoengineering] still a fringe topic? Partly…because of the stupidity of the anti-environmentalist right ….But largely…because the people who think Earth in the Balance was one of Al Gore’s accomplishments, rather than one of the strongest reasons to doubt his fitness to be President, really don’t want a non-Gaian, non-regulatory solution to their most precious problem.”

Dealing responsibly with our changing climate requires a portfolio of strategies, probably including geoengineering. Greens will be sorry if they dismiss this out-of-hand, for this will raise questions about credibility and sincerity. Critics will claim their real motives are to force us into austerity to atone for our environmental sins.